Susceptibility to Intergranular Corrosion of HR3C Steel Evaluated by Electrochemical Potentiodynamic Reactivation(EPR)

The microstructure of HR3C steel was investigated using optical microscopy, scanning electron microscopy and X-ray diffraction. And the susceptibility to intergranular corrosion of HR3C steel was evaluated by electrochemical potentiodynamic reactivation(EPR). The results show that the microstructure of HR3C steel consisted of γ-matrix and a small amount of discontinuous precipitated phases of M23C6 and Nb(C,N). There was no obvious peak in the depolarization process related to the potentiodynamic reactivation curve, and austenitic grain boundaries did not exhibit traces of corrosion and corrosion grooves, indicating that HR3C steel as received has excellent resistance to intergranular corrosion.